Field of the Invention
The present disclosure relates to a method of manufacturing a jelly roll-type electrode assembly and a method of manufacturing a polymer secondary battery including the electrode assembly, and more particularly, to a method of manufacturing a jelly roll-type electrode assembly allowing for improved design flexibility and a method of manufacturing a polymer secondary battery including the electrode assembly.
Description of the Related Art
In general, a jelly roll-type polymer battery is manufactured by laminating a cathode and an anode with a separator disposed therebetween and winding the cathode and anode laminate in a single direction. A schematic process of manufacturing such a jelly roll-type electrode assembly and a jelly roll-type electrode assembly obtained by the process are illustrated in FIG. 1.
In FIG. 1, a jelly roll-type electrode assembly 1 may be obtained by winding a plurality of electrodes in a single direction, unlike a method of manufacturing an electrode assembly by laminating a plurality of electrodes as a stack-type electrode assembly, or a stacking/folding type electrode assembly, which does not require a process of laminating the plurality of electrodes and a separator. Accordingly, this method has advantages in that the manufacturing process is relatively simpler than the other methods, which results in easy production.
However, when the electrode assembly 1 is manufactured as such a jelly roll type electrode assembly, two linear electrodes, that is, an anode 31 and a cathode 33, both of which generally have a rectangular shape elongated in a single direction, and a separator 50 are used, as illustrated in FIG. 1. Therefore, the jelly roll-type electrode assembly 1, obtained as described above by laminating the anode 31 and the cathode 33 with the separator 50 disposed therebetween and simply winding the anode 31 and the cathode 33, and a battery obtained using such an electrode assembly typically have a rectangular shape as illustrated in FIG. 1, which may restrict the shapes of batteries. As a result, a degree of design freedom may be significantly reduced, compared to stack-type or stacking/folding-type polymer batteries.
Korean Patent Publication No. 2002-0082729 discloses a method of manufacturing a button-type lithium battery in which a jelly roll type battery is manufactured by coupling circular electrode collector plates to a quadrilateral connection unit. However, the secondary battery provided in the patent document is limited to a button-type lithium battery. In particular, the patent document discloses that a separator is disposed between a cathode collector plate and an anode collector plate, but does not specifically describe the shape of the separator. Also, the patent document does not disclose specific contents regarding the shape of the separator corresponding to the shape of the collector plates.
Accordingly, a degree of design freedom may be limited when the quadrilateral separator is used, and when a separator having the same shape as the collector plate is used, the separator has to be processed to have the same shape as the collector plate. Additionally, when a separator is processed to have a specific shape, the separator should be realized in advance in a shape corresponding to the shape of an electrode plate. In this case, a certain degree of dimensional precision is required. In particular, the separator is typically a very thin film formed of a plastic material, and thus is not easily cat to have a predetermined shape, which results in difficulty in realizing a desired shape.
An aspect of the present disclosure may provide methods of manufacturing a jelly roll-type electrode assembly and a polymer secondary battery, both of which exhibit excellent design flexibility, in the manufacturing of the jelly roll-type electrode assembly and the polymer secondary battery, whose production process can easily be simplified.
An aspect of the present disclosure may also provide an effective method of processing the separator used in the manufacturing of the electrode assembly to correspond to the shape of the electrode assembly.